In different fields of x-ray diagnostics, fluoroscopy systems featuring different x-ray detector dimensions are generally used nowadays. A flat panel detector with an edge length of approximately 20 cm×20 cm is used within the field of cardiology and a flat panel detector with an edge length of approximately 30 cm×40 cm is used within the field of radiology for instance. The main reason for this consists in the need to find a suitable compromise between covering the organ of interest and the required angulations, e.g. of a C-arm, according to the application, since a small x-ray detector enables collisions to be more easily avoided and enables correspondingly higher angulations to be carried out, but it is nevertheless impossible for the whole heart, including the coronary vessels, to be mapped for instance.
With the increasing spread of (cardio) vascular centers, it was important, even with the exceptional use of large x-ray detectors (e.g. 42 cm×42 cm edge length) to achieve flexible configurations with extended angulation possibilities in C-arm x-ray devices for instance. In the case of a small measuring field which only requires a part of the sensor surface of the x-ray detector, one possibility consists here in eccentrically superimposing the small measuring field on the large x-ray detector. The so-called eccentric collimation enables collisions to be avoided and accordingly a higher angulation.
If a measuring field on the sensor surface of the x-ray detector is however displaced in a translatory fashion from a center position into an eccentric position, a different examination area is superimposed on the eccentrically positioned measuring field than on the center positioned measuring field. If the superimposed examination area is to remain the same however, the user must manually move the examination table, on which the object with the examination area is located, since the isocenter, which generally coincides with the center point of the examination area, of the C-arm is fixed.